20 research outputs found
Role of hydrographical parameters and total organic carbon on mercury allocation along the riverine transect of Beypore, south-west coast of India
1419-1426Distribution of total mercury (THg) was carried out in the sediments of Beypore estuary. The THg concentration in surface sediments varied from 0.03 ppm to 0.17 ppm. The pollution index approach using contamination factor (CF) revealed that the sampling stations are moderately contaminated with respect to mercury. Further, the effects of hydrographical parameters (pH, salinity, dissolved oxygen) and total organic carbon (TOC) of the sediment were studied over the spatial distribution of mercury (Hg). Correlation analysis unveiled THg exhibited significant positive correlations with TOC (R=0.91) and salinity (R=0.744). However significant inverse correlation was observed between pH and Hg (R =-0.93). The C: N ratios suggest that the organic matter is labile in nature. Total organic carbon was found to control the distribution of Hg. It is the first base line study in this estuary
Spatial variability of biochemical composition in coral reef sediments of Kavaratti and Pitti islands, Lakshadweep archipelago
369-378In this study, variability of biochemical composition in the surficial coral reef sediments of Kavaratti and Pitti islands in Lakshadweeep archipelago was investigated. Biochemical composition of sedimentary organic matter from the study area was characterized by the dominance of proteins in Pitti and carbohydrates in Kavaratti over lipids. The percentage ratio of the labile to total organic matter indicated that most of the deposited organic matter was refractory in both environments. The higher PRT:CHO ratios in Pitti sediments compared to that of Kavaratti indicated that in the former there was low dead organic matter accumulation. The lower LPD:CHO ratios estimated for sediments in both islands indicated low quality of labile organic matter to support benthic fauna
How to motivate people for donor eyes with active support and participation of NGOs
Background: Corneal diseases are among the major causes of vision loss and blindness in the world today, after cataract and glaucoma. In India, it is estimated that there are approximately 6.8 million people who have vision less than 6/60 in at least one eye due to corneal diseases. On an average, the country needs 200,000 corneas in a year, and only 44,806 are collected. Therefore, creating awareness amongst the masses and encouraging them to pledge their eyes for donation is critical. We utilized the help of local voluntary, social, and religious organizations for the implementation of the awareness and motivation program.Methods: Authors utilized the help of local voluntary, social, and religious organizations for the selection of sites, local publicity, arrangement and mobilization of people and other infrastructure. Schools, colleges, clubs, organizations, trade union offices, public functions, etc were utilized for the arrangement of this awareness and motivation camps.Results: As a result of the eye donation awareness and motivation programs we got 1035 eyes in the past 12 years. Starting with 24 eyes in the first year rising to 126eyes in the 12th year. 64% of the eyes received were utilized for keratoplasty and 36% were used for research purposes.Conclusions: Out experiences has convinced us the important role of social and religious organization and its leaders in spreading the message of eye donation among people. These organizations have an active role in creating awareness and motivation of eye donation to clear the backlog of corneal blindness in India
A characteristic study of humic acids isolated from Arctic fjord sediments
Humic substances are ubiquitous natural materials found in sediments as a product of biochemical transformation reactions representing a significant proportion of organic carbon cycle on earth. This study involves the analysis of humic substances with special emphasis on humic acids (HAs) in sediments collected from the Kongsfjorden System of Arctic region in June, 2017. The characterization of the isolated HAs were done using various spectroscopic techniques viz. UV-visible, Fluorescence, FTIR and NMR. Isolated HAs were also undergone for elemental analysis along with other characterization. The UV spectral analysis results with a lower E4/E6 ratio suggesting the presence of HAs with high degree of aromaticity and condensation. Indications for the presence of hydroxyl, methyl, methylene, carbonyl, carboxyl, phenol, alcohol and amide groups were obtained from the FTIR spectrums of HAs. NMR spectral characteristics also confirm the presence of OH group as well as the presence of CH protons adjacent to C=X, were X can be any electronegative element. This also confirms the presence of carbonyl group which is also evident in the FTIR spectral studies. Presence of aliphatic regions slightly more dominated with long chain and/or alicyclic moieties rather than methyl groups was also inferred from the results of NMR
Coral Reef Ecosystem of Lakshadweep Archipelago –A Biogeochemical Facsimile
The present study focuses on the biochemical aspects of six islands belonging to Lakshadweep Archipelago – namely Kavaratti, Kadamath, Kiltan, Androth, Agathy and Minicoy. Lakshadweep, which is an area biologically significant due to isolation from the major coastline, remains as one of the least studied areas in Indian Ocean. The work, processed out the distributional pattern of trace metals among the biotic (corols, sea weeds and sea grass) and abiotic component (sediments) of ecosystem. An effort is made to picturise the spatial distribution pattern of different forms of nitrogen and phosphorus in the various sedimentary environments of the study area. Studies on the biogeochemical and nutrient aspects of the concerned study area scanty. In Lakshadweep, the local life is very dependent on reefs and its resources. The important stress which produce a threatening effort on the existence for coral reefs are anthropogenic-namely-organic and inorganic pollution from sewage, agricultural and industrial waters, sediment damage from excessive land cleaning, and over exploitation particularly through destructive fishing methods. In addition these one other more localized or less service anthropogenic stress: pollution by oil and other hydrocarbons, complex organic molecular and heavy metal pollution, and destructive engineering practices
Humic acids from an Arctic fjord, Krossfjorden, Spitsbergen
Humic substances are ubiquitous materials found in terrestrial and aquatic ecosystems. Humic acids, a diagenetic product can interact with various components present in aquatic sediments. The present research is on the evaluation of sedimentary humic acids from the Krossfjorden glacial fjord situated within the Svalbard archipelago. The results of this study are needed to understand the structural characteristics of humic acids isolated from the fjord. Surface sediment samples were collected from four stations throughout the fjord during a summer period in 2018. Various spectroscopic techniques such as UV-visible, Fourier-transform infrared spectroscopy (FTIR), and Nuclear magnetic resonance spectroscopy (NMR) were applied for studying the humic acids. The elemental composition as well as the presence of tannin and lignin were also analyzed. The results of
this study revealed the variation in the structure of humic acids from aliphatic to aromatic from the outer to the inner region of the fjord. This change in humic acids was well supported by the FTIR and NMR results with differences in the spectrums
Antibacterial and Catalytic Efficacy of Biosynthesized Silver Nanoparticles Using Marine Seaweed Padina Tetrasromatica
Utilization of renewable marine resources for the biosynthesis of metal nanoparticles is an innovative area in the current nanotechnology research. The present article reports a simple environmentally benign method for the synthesis of silver nanoparticles using aqueous extract of marine brown seaweed Padina Tetrastromatica, which act as both the reducing and stabilising agent. The formation, morphology and crystalline nature of the synthesised silver nanoparticles were determined using UV-Visible Spectroscopy, Transmission electron microscopy, Selected area electron diffraction and X-ray diffraction techniques. The surface plasmon resonance peak at 424 nm in the UV-Visible spectrum confirmed the formation of silver nanoparticles. The biosynthesised silver nanoparticles were almost spherical with an average size of 15 nm. Crystalline nature of silver nanoparticles is evident from the characteristic peaks in the X-ray diffraction pattern, bright circular spots in the selected area electron diffraction pattern and clear lattice fringes in the High resolution Transmission electron microscopy images. Fourier transform infrared spectroscopic analysis revealed the presence of functional bio active metabolites in seaweed extract which is responsible for the formation and efficient stabilization of the nanoparticles. The biosynthesised silver nanoparticles show excellent antimicrobial activity against Escherichia coli and Aeromonas hydrophila. They also show very good catalytic activity for the reduction of methylene blue in the presence of NaBH4 in aqueous medium. Thus the green synthesised nanoparticles are expected to be a promising candidate for the application in diverse fields
Forms of Nitrogen (NO 3 - -N; NO 2 - -N and NH 2 CONH 2 -N) and their relations to A.O.U. in the Indian coastal waters of Arabian Sea
The distribution of three important dissolved forms of nitrogen, viz. nitrate, nitrite and urea in the surface and bottom
water samples collected from 27 selected hydrographic profiles, in the Arabian Sea, along the west coast of India is
described. Of the three forms, nitrate concentrations were the highest and comparatively higher concentrations were
observed in the bottom water. Decomposition of organic matter resulting in the release of the thermodynamically
stable nitrogen species, i.e. nitrate, may be the major factor resulting in higher nitrate concentrations at these
depths, where the water is also characterized by low values of dissolved oxygen and temperature. The significant
positive correlation between A.O.U. and nitrate of the bottom water samples emphasizes the role of oxidative
decomposition of organic matter which plays an active role in reducing the oxygen concentrations below the
theoretical values since at this depth ( 200 m) the net production is taken to be zero. This is also evidenced by
the negative correlation of nitrate with dissolved oxygen and temperature, for the bottom samplesCochin
University of Science and TechnologyChemistry and Ecology, 2002, Vol. 18(3–4), pp. 233–24